Additive single-piece bore-cooled combustor dome

ABSTRACT

Methods and apparatus for an additive, single-piece, bore-cooled combustor dome or liner are disclosed. An example combustor dome forms an integral part including: a plurality of first openings; a plurality of second openings; and a plurality of passages formed in the combustor dome connecting respective ones of the plurality of first openings with respective ones of the plurality of second openings. The combustor dome is configured to allow air to enter through the plurality of first openings and travel through the plurality of passages to exit through the plurality of second openings, the air to transfer heat from the combustion section.

FIELD OF THE DISCLOSURE

This disclosure relates generally to turbine engines and, more particularly, to additive single-piece, bore-cooled combustor domes.

BACKGROUND

Turbine engines are some of the most widely-used power generating technologies. Gas turbines are an example of an internal combustion engine that uses a burning air-fuel mixture to produce hot gases that spin the turbine, thereby generating power. Application of gas turbines can be found in aircraft, trains, ships, electrical generators, gas compressors, and pumps. For example, modern aircraft rely on a variety of gas turbine engines as part of a propulsion system to generate thrust, including a turbojet, a turbofan, a turboprop, and an afterburning turbojet. Such engines include a combustion section, a compressor section, a turbine section, and an inlet, providing high power output with a high thermal efficiency. However, portions of such engines can become hot during operation and can be difficult to cool.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of an example high-bypass turbofan-type gas turbine engine.

FIG. 2 illustrates an example implementation of a combustion section of the example gas turbine engine of FIG. 1 .

FIG. 3 illustrates an example implementation of the combustion section of the example gas turbine engine of FIG. 1 .

FIG. 4 illustrates an example implementation of the combustion section of the example gas turbine engine of FIG. 1 .

FIG. 5-10 illustrate additional views of the example enclosure of the combustion section including the combustor dome surrounding the combustion chamber.

FIG. 11 is a flow diagram of an example additive manufacturing process to form the combustor dome of the example of FIGS. 3-10 .

DETAILED DESCRIPTION

Certain examples provide improved cooling of a combustor in an engine. Certain examples provide a combustor dome with an integrated cooling mechanism for improved cooling of the combustor. Certain examples provide a combustor dome formed using additive manufacturing with integrated cooling tubes. Certain examples provide a bore-cooled combustor dome produced as an integrated part using additive manufacturing.

A combustion section or “combustor” is a portion of a gas engine, such as a gas turbine engine, a jet engine, etc., in which fuel ignites to heat air at a constant pressure. Air and fuel are mixed in the combustion section, and the heated, pressurized air is directed through guide vanes, nozzle, etc., to power the turbine. As a result of the ignition of fuel and heating of air, the combustion section is also heated. The heated combustion section must be cooled to maintain stability and desired performance, for example. While prior implementations required multiple components and implemented impingement cooling, by which air would travel in a direction normal to the combustor casing and impinge or contact the combustion section via openings or holes to cool the combustor, certain examples integrate cooling bores, tubes, or passageways that extend along a dome forming a top of the combustor section. In a single piece, cooling air can travel along the combustor section within the combustor dome to extract heat and cool the combustor section.

In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific examples that may be practiced. These examples are described in sufficient detail to enable one skilled in the art to practice the subject matter, and it is to be understood that other examples may be utilized. The following detailed description is therefore, provided to describe an exemplary implementation and not to be taken limiting on the scope of the subject matter described in this disclosure. Certain features from different aspects of the following description may be combined to form yet new aspects of the subject matter discussed below.

The figures are not to scale. Instead, the thickness of the layers or regions may be enlarged in the drawings. In general, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. As used in this patent, stating that any part (e.g., a layer, film, area, region, or plate) is in any way on (e.g., positioned on, located on, disposed on, or formed on, etc.) another part, indicates that the referenced part is either in contact with the other part, or that the referenced part is above the other part with one or more intermediate part(s) located therebetween. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. Stating that any part is in “contact” with another part means that there is no intermediate part between the two parts.

Descriptors “first,” “second,” “third,” etc., are used herein when identifying multiple elements or components which may be referred to separately. Unless otherwise specified or understood based on their context of use, such descriptors are not intended to impute any meaning of priority, physical order or arrangement in a list, or ordering in time but are merely used as labels for referring to multiple elements or components separately for ease of understanding the disclosed examples. In some examples, the descriptor “first” may be used to refer to an element in the detailed description, while the same element may be referred to in a claim with a different descriptor such as “second” or “third.” In such instances, it should be understood that such descriptors are used merely for ease of referencing multiple elements or components.

The terms “upstream” and “downstream” refer to the relative direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the direction from which the fluid flows, and “downstream” refers to the direction to which the fluid flows.

Various terms are used herein to describe the orientation of features. As used herein, the orientation of features, forces and moments are described with reference to the yaw axis, pitch axis, and roll axis of the vehicle associated with the features, forces and moments. In general, the attached figures are annotated with reference to the axial direction, radial direction, and circumferential direction of the vehicle associated with the features, forces and moments. In general, the attached figures are annotated with a set of axes including the axial axis A, the radial axis R, and the circumferential axis C.

In some examples used herein, the term “substantially” is used to describe a relationship between two parts that is within three degrees of the stated relationship (e.g., a substantially colinear relationship is within three degrees of being linear, a substantially perpendicular relationship is within three degrees of being perpendicular, a substantially parallel relationship is within three degrees of being parallel, etc.). As used herein, an object is substantially specifically if the object has a radius that vary within 15% of the average radius of the object.

“Including” and “comprising” (and all forms and tenses thereof) are used herein to be open ended terms. Thus, whenever a claim employs any form of “include” or “comprise” (e.g., comprises, includes, comprising, including, having, etc.) as a preamble or within a claim recitation of any kind, it is to be understood that additional elements, terms, etc. may be present without falling outside the scope of the corresponding claim or recitation. As used herein, when the phrase “at least” is used as the transition term in, for example, a preamble of a claim, it is open-ended in the same manner as the term “comprising” and “including” are open ended. The term “and/or” when used, for example, in a form such as A, B, and/or C refers to any combination or subset of A, B, C such as (1) A alone, (2) B alone, (3) C alone, (4) A with B, (5) A with C, (6) B with C, and (7) A with B and with C. As used herein in the context of describing structures, components, items, objects and/or things, the phrase “at least one of A and B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. Similarly, as used herein in the context of describing structures, components, items, objects and/or things, the phrase “at least one of A or B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. As used herein in the context of describing the performance or execution of processes, instructions, actions, activities and/or steps, the phrase “at least one of A and B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. Similarly, as used herein in the context of describing the performance or execution of processes, instructions, actions, activities and/or steps, the phrase “at least one of A or B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B.

As used herein, singular references (e.g., “a”, “an”, “first”, “second”, etc.) do not exclude a plurality. The term “a” or “an” entity, as used herein, refers to one or more of that entity. The terms “a” (or “an”), “one or more”, and “at least one” can be used interchangeably herein. Furthermore, although individually listed, a plurality of means, elements or method actions may be implemented by, e.g., a single unit or processor. Additionally, although individual features may be included in different examples or claims, these may possibly be combined, and the inclusion in different examples or claims does not imply that a combination of features is not feasible and/or advantageous.

As used herein, the terms “system,” “unit,” “module,”, “engine,”, “component,” etc., may include a hardware and/or software system that operates to perform one or more functions. For example, a module, unit, or system may include a computer processor, controller, and/or other logic-based device that performs operations based on instructions stored on a tangible and non-transitory computer readable storage medium, such as a computer memory. Alternatively, a module, unit, or system may include a hard-wires device that performs operations based on hard-wired logic of the device. Various modules, units, engines, and/or systems shown in the attached figures may represent the hardware that operates based on software or hardwired instructions, the software that directs hardware to perform the operations, or a combination thereof.

A turbine engine, also called a combustion turbine or a gas turbine, is a type of internal combustion engine. Turbine engines are commonly utilized in aircraft and power-generation applications. As used herein, the terms “asset,” “aircraft turbine engine,” “gas turbine,” “land-based turbine engine,” and “turbine engine” are used interchangeably. A basic operation of the turbine engine includes an intake of fresh atmospheric air flow through the front of the turbine engine with a fan. In some examples, the air flow travels through an intermediate-pressure compressor or a booster compressor located between the fan and a high-pressure compressor. The booster compressor is used to supercharge or boost the pressure of the air flow prior to the air flow entering the high-pressure compressor. The air flow can then travel through the high-pressure compressor that further pressurizes the air flow. The high-pressure compressor includes a group of blades attached to a shaft. The blades spin at high speed and subsequently compress the air flow. The high-pressure compressor then feeds the pressurized air flow to a combustion chamber. In some examples, the high-pressure compressor feeds the pressurized air flow at speeds of hundreds of miles per hour. In some instances, the combustion chamber includes one or more rings of fuel injectors that inject a steady stream of fuel into the combustion chamber, where the fuel mixes with the pressurized air flow.

In the combustion chamber of the turbine engine, the fuel is ignited with an electric spark provided by an igniter, where the fuel in some examples burns at temperatures of more than 1,000 degrees Celsius. The resulting combustion produces a high-temperature, high-pressure gas stream (e.g., hot combustion gas) that passes through another group of blades of a turbine. The turbine includes an intricate array of alternating rotating and stationary airfoil-section blades. As the hot combustion gas passes through the turbine, the hot combustion gas expands, causing the rotating blades to spin. The rotating blades serve at least two purposes. A first purpose of the rotating blades is to drive the booster compressor and/or the high-pressure compressor to draw more pressured air into the combustion chamber. For example, the turbine is attached to the same shaft as the high-pressure compressor in a direct-drive configuration, thus, the spinning of the turbine causes the high-pressure compressor to spin. A second purpose of the rotating blades is to spin a generator operatively coupled to the turbine section to produce electricity, and/or to drive a rotor, fan or propeller. For example, the turbine can generate electricity to be used by an aircraft, a power station, etc. In the example of an aircraft turbine engine, after passing through the turbine, the hot combustion gas exits the aircraft turbine engine through a nozzle at the back of the aircraft turbine engine.

Referring now to the drawings, wherein identical numerals indicate the same elements throughout the figures, FIG. 1 is a schematic cross-sectional view of an example high-bypass turbofan-type gas turbine engine 110 (“turbofan engine 110”). While the illustrated example is a high-bypass turbofan engine, the principles of the presently described technology are also applicable to other types of engines, such as low-bypass turbofans, turbojets, turboprops, etc. As shown in FIG. 1 , the turbofan engine 110 defines a longitudinal or axial centerline axis 112 extending therethrough for reference. FIG. 1 also includes an annotated directional diagram with reference to an axial direction A, a radial direction R, and a circumferential direction C. In general, as used herein, the axial direction A is a direction that extends generally parallel to the centerline axis 112, the radial direction R is a direction that extends orthogonally outwardly from the centerline axis 112, and the circumferential direction C is a direction that extends concentrically around the centerline axis 112.

In general, the turbofan engine 110 includes a core turbine or gas turbine engine 114 (“core turbine engine 114”) disposed downstream from a fan section 116. The core turbine engine 114 includes a substantially tubular outer casing 118 that defines an annular inlet 120. The outer casing 118 can be formed from a single casing or multiple casings. The outer casing 118 encloses, in serial flow relationship, a compressor section having a booster or low pressure compressor 122 (“LP compressor 122”) and a high pressure compressor 124 (“HP compressor 124”), a combustion section 126, a turbine section having a high pressure turbine 128 (“HP turbine 128”) and a low pressure turbine 130 (“LP turbine 130”), and an exhaust section 132. A high pressure shaft or spool 134 (“HP shaft 134”) drivingly couples the HP turbine 128 and the HP compressor 124. A low pressure shaft or spool 136 (“LP shaft 136”) drivingly couples the LP turbine 130 and the LP compressor 122. The LP shaft 136 can also couple to a fan spool or shaft 138 of the fan section 116. In some examples, the LP shaft 136 is coupled directly to the fan shaft 138 (e.g., a direct-drive configuration). In alternative configurations, the LP shaft 136 can couple to the fan shaft 138 via a reduction gear 139 (e.g., an indirect-drive or geared-drive configuration).

As shown in FIG. 1 , the fan section 116 includes a plurality of fan blades 140 coupled to and extending radially outwardly from the fan shaft 138. An annular fan casing or nacelle 142 circumferentially encloses the fan section 116 and/or at least a portion of the core turbine engine 114. The nacelle 142 can be supported relative to the core turbine engine 114 by a plurality of circumferentially-spaced apart outlet guide vanes 144. Furthermore, a downstream section 146 of the nacelle 142 can enclose an outer portion of the core turbine engine 114 to define a bypass airflow passage 148 therebetween.

As illustrated in FIG. 1 , air 150 enters an inlet portion 152 of the turbofan engine 110 during operation thereof. A first portion 154 of the air 150 flows into the bypass airflow passage 148, while a second portion 156 of the air 150 flows into the inlet 120 of the LP compressor 122. One or more sequential stages of LP compressor stator vanes 170 and LP compressor rotor blades 172 coupled to the LP shaft 136 progressively compress the second portion 156 of the air 150 flowing through the LP compressor 122 en route to the HP compressor 124. Next, one or more sequential stages of HP compressor stator vanes 174 and HP compressor rotor blades 176 coupled to the HP shaft 134 further compress the second portion 156 of the air 150 flowing through the HP compressor 124. This provides compressed air 158 to the combustion section 126 where it mixes with fuel and burns to provide combustion gases 160.

The combustion gases 160 flow through the HP turbine 128 where one or more sequential stages of HP turbine stator vanes 166 and HP turbine rotor blades 168 coupled to the HP shaft 134 extract a first portion of kinetic and/or thermal energy therefrom. This energy extraction supports operation of the HP compressor 124. The combustion gases 160 then flow through the LP turbine 130 where one or more sequential stages of LP turbine stator vanes 162 and LP turbine rotor blades 164 coupled to the LP shaft 136 extract a second portion of thermal and/or kinetic energy therefrom. This energy extraction causes the LP shaft 136 to rotate, thereby supporting operation of the LP compressor 122 and/or rotation of the fan shaft 138. The combustion gases 160 then exit the core turbine engine 114 through the exhaust section 132 thereof. A turbine frame 161 with a fairing assembly is located between the HP turbine 128 and the LP turbine 130. The turbine frame 161 acts as a supporting structure, connecting a high-pressure shaft's rear bearing with the turbine housing and forming an aerodynamic transition duct between the HP turbine 128 and the LP turbine 130. Fairings form a flow path between the high-pressure and low-pressure turbines and can be formed using metallic castings (e.g., nickel-based cast metallic alloys, etc.).

Along with the turbofan engine 110, the core turbine engine 114 serves a similar purpose and is exposed to a similar environment in land-based gas turbines, turbojet engines in which the ratio of the first portion 154 of the air 150 to the second portion 156 of the air 150 is less than that of a turbofan, and unducted fan engines in which the fan section 116 is devoid of the nacelle 142. In each of the turbofan, turbojet, and unducted engines, a speed reduction device (e.g., the reduction gear 139) can be included between any shafts and spools. For example, the reduction gear 139 is disposed between the LP shaft 136 and the fan shaft 138 of the fan section 116.

As described above with respect to FIG. 1 , the turbine frame 161 is located between the HP turbine 128 and the LP turbine 130 to connect the high-pressure shaft's rear bearing with the turbine housing and form an aerodynamic transition duct between the HP turbine 128 and the LP turbine 130. As such, air flows through the turbine frame 161 between the HP turbine 128 and the LP turbine 130. The flow of air can be hot, which can result in deflection and decrease in aerodynamic performance.

In certain examples, the combustion section 126 (also referred to herein as the combustor 126) includes a combustion chamber defined by a shell including a lower surface or liner and an upper surface or liner (also referred to herein as a combustor dome). FIG. 2 illustrates an example implementation of the combustion section 126. As shown in the example of FIG. 2 , a cross-sectional view is provided of the combustion section 126 in accordance with certain examples of the present disclosure. Notably, FIG. 2 illustrates only portions of combustion section 126 for the purpose of explaining aspects of the present subject matter, while other components are removed for clarity. In addition, the combustion section 126 is only one example combustor and other types and configurations of combustor assemblies can be used according to alternative examples.

As shown in the example of FIG. 2 , the combustion section 126 generally includes a combustor dome 202 that defines a combustion chamber 204 within which fuel and air are combusted to support the turbofan engine 110 operation. More specifically, the combustor dome 202 is defined at least in part by one or more combustor liners or combustor walls 206 that together at least partially define a combustion chamber 204 therebetween. The example the combustor dome 202, or more particularly the combustor wall 206, extends between a forward end 208 and an aft end 210.

In addition, the combustor dome or liner 202 may generally define features for receiving components to support the combustion process. For example, as shown in FIG. 2 , the combustor dome 202 may define a plurality of circumferentially spaced fuel injection ports 212 proximate the forward end 208. The combustion section 126 further includes a plurality of fuel injector assemblies, referred to herein as fuel injectors (not shown), which may include premixers, fuel-air mixers, or similar assemblies, and are generally configured for supplying a mixture of fuel and air into the combustion chamber 204 to facilitate combustion. In certain examples, fuel injectors are inserted into each of the plurality of fuel injection ports 212.

In addition, the example combustion section 126 can include one or more igniters or igniter assemblies (not shown) which are inserted into or positioned proximate to the combustion chamber 204 to ignite the fuel/air mixture provided therein. More specifically, as illustrated in FIG. 2 , the combustor wall 206 defines one or more igniter ports 214 for receiving such an igniter assembly such that the igniter extends into the combustion chamber 204 through the igniter port 214. A ferrule 220 is positioned in the igniter port 214 with respect to the combustor wall 206. The ferrule 220 defines an axial direction A2 and a radial direction R2. All or part of the combustion section 126 can be implemented using additive manufacturing.

FIG. 3 provides a partial view of the combustion section 126 of FIGS. 1-2 including an example implementation of the combustor dome 202. In the example of FIG. 3 , the combustion section 126 includes the combustion chamber 204 formed of a housing including the upper liner or combustor dome 202 with the ferrule 220, which allows air and/or a mix of fuel and air to enter the combustion chamber 204 from the igniter port 214 (not labeled in this view). The lower combustor wall or liner 206 (not shown in this view) completes the enclosure of the combustion chamber 204 of the example combustion section 126. A plurality of first openings 310 (e.g., holes, etc.) in the combustor dome 202 provide entry at a first end (e.g., a cool end) of the combustor dome 202 for cooling air to travel through passages (not shown in this view) extending through the combustor dome 202. The air draws heat from the combustion chamber 204 and exits as heated air from a plurality of second openings 320 (e.g., holes, etc.) at a second end (e.g., a hot end) of the combustor dome or liner 202. In certain examples, the combustor dome 202 is formed via additive manufacturing with the openings 310, 320 and tubes connecting the openings 310, 320 formed integral to the combustor dome or liner 202 in the additive manufacturing process (described further below).

FIG. 4 illustrates another view of the example combustor dome 202 shown in FIG. 3 . In the example view of FIG. 4 , the combustor dome 202 has been made transparent to expose a plurality of passages 410, also referred to herein as bores or tubes, formed inside the combustor dome 202 connecting the plurality of first openings 310 with the plurality of second openings 320. As disclosed above, an additive manufacturing process can be used to form the combustor dome 202 including the passages 410 with the plurality of first openings 310 and the plurality of second openings 320. As such, the combustor dome 202 is formed as an integral part via additive manufacturing and/or other manufacturing process. For example, the combustor dome 202 is formed as a single unified structure formed together via an additive manufacturing process, subtractive manufacturing process, and/or other manufacturing process, rather than formed as separate pieces that are then assembled together.

During operation of the combustion section 126, cooling air enters the plurality of first openings 310. Combustion of fuel and air in the combustion chamber 204 generates heat, which heats the combustor dome 202 as well as the air in the combustion chamber 204 that will be used to generate power. As the air travels along the passages 410 through the combustor dome 202 surrounding the combustion chamber 204, some of the heat from the combustor dome 202 is absorbed by the air. The heated air exits the combustor dome 202 via its passages or bores 410 at the plurality of second openings 320. As such, the temperature of the combustor dome 202 can be regulated and prevented from overheating. Overheating of the combustor dome 202 could result in failure of the combustion section 126 or at least a decrease in performance, for example.

Thus, certain examples provide a bore-cooled combustor dome 202 using additive manufacturing to position cooling air closer to the hot side of the combustor dome 202 and, therefore, allow the combustion section 126 to be run at hotter conditions than traditional manufacturing. Manufacture of the combustor dome 202 via additive manufacturing involves no brazes, welds, or additional heat shields and eliminates the need for impingement, requiring less cooling air, for example. Certain examples provide a single piece combustor dome 202 with passages 410 that bring cooling air through an annulus at openings 310, 320 and distribute the air evenly through the dome plate structure. Rather than a multi-component dome with impingement and film cooling, certain examples provide a single-piece, integrated combustor dome 202 that is more efficient at cooling the hot side of the metal of the combustor dome 202, allowing for the elimination of costly coated heat shields and overall machine reduction in fuel consumption.

Using the integral combustor dome 202, deflectors and impingement cooled hardware can be eliminated. Additionally, bore cooling in the combustor dome 202 can replace film cooling and/or thermal protective coating. Bore cooling provides a uniform, full-coverage cooling design with an exit flow that can form a starter flow for liner nugget cooling, for example. In certain examples, the plurality of first openings 310 for bore-cooling passages 410 are customizable to reduce entrance losses and drive uniform flow distribution across passages. Through the integral combustor dome 202, assembly of subcomponents is eliminated and, therefore, associated errors, fasteners, clamps, etc., are also eliminated. Additive manufacturing of the integral combustor dome 202 removes common brazes and welds from high thermal gradient locations, increasing durability of the combustor dome 202 and associated combustion section 126, for example. As such, the combustor dome 202 has fewer points of failure than with prior designs. Further, repairs can be simplified and time off-wing can be reduced. Additionally, in certain examples, integrated features, such as fuel nozzle interface components, etc., permit finish machining as a unit rather than separated features that are typically associated with individual subcomponents on conventional dome designs.

In certain examples, a size/diameter of the passages 410 is customizable to optimize and/or otherwise account for aerodynamics and/or heat transfer. As such, passage 410 sizes and/or other parameters can be modeled, simulated, etc., to determine a mix of aerodynamic and/or heat transfer benefit and/or compliance with other operating and/or safety requirement, for example. Rather than a constant diameter flow passage, flow passages 410 and/or associated openings 310, 320 can be uniquely sized to reduce pressure drop, maximize cooling, and/or other criterion, for example.

FIG. 5 illustrates an additional view of the example enclosure of the combustion section 126 including the combustor dome 202 surrounding the combustion chamber 204. The plurality of first openings 310 are positioned around the ferrule 220 and allow air to enter the passages 410 (not shown in this view) and exit the plurality of second openings 320 (not shown in this view) to cool the combustion chamber 204 through the combustor dome 202. FIG. 6 shows an angled view of the example of FIG. 5 . FIG. 7 illustrates an example view from an interior of the combustion chamber 204 showing the plurality of second openings 320 extending through the combustor dome 202 over the igniter port 214.

FIGS. 8-10 show transparent views of the combustor dome 202 depicting the passages 410 allowing air to flow through the combustor dome 202 from the plurality of first openings 310 to the plurality of second openings 320 around the combustion chamber 204. Using the improved structure of the combustor dome 202, as shown in the examples of FIGS. 3-10 , provides a technical effect of improved cooling of the combustion chamber 204. This improved cooling occurs without sacrificing structural integrity of the combustion section 126 and without involving additional material or components. Rather, the openings 310, 320 and passages 410 are integrated into the combustor dome 202 itself at manufacture.

In general, the example combustion section 126 described herein can be manufactured or formed using any suitable process. However, in accordance with several aspects of the present subject matter, some or all of combustion section 126 can be formed using an additive manufacturing process, such as a three-dimensional (3D) printing process. The use of such a process enables all or part of the combustion section 126, such as the combustor dome 202, to be formed integrally, as a single monolithic component, or as any suitable number of sub-components. In particular, the manufacturing process may allow the combustor dome 202 to be integrally formed and include a variety of features not possible when using prior manufacturing methods. For example, the additive manufacturing methods described herein enable the manufacture of the combustor dome 202 including unique features, configurations, thicknesses, materials, densities, and structures not possible using prior manufacturing methods. For example, the passages 410 and associated openings 310, 320 can be formed integrally in the combustor dome 202 using additive manufacturing. Such integration would not be possible using other prior manufacturing technologies.

As used herein, the terms “additively manufactured” or “additive manufacturing techniques or processes” refer generally to manufacturing processes wherein successive layers of material(s) are provided on each other to “build-up,” layer-by-layer, a three-dimensional component. The successive layers generally fuse together to form a monolithic component which may have a variety of integral sub-components. Although additive manufacturing technology is described herein as enabling fabrication of complex objects by building objects point-by-point, layer-by-layer, typically in a vertical direction, other methods of fabrication are possible and within the scope of the present subject matter. For example, although the discussion herein refers to the addition of material to form successive layers, one skilled in the art will appreciate that the methods and structures disclosed herein may be practiced with any additive manufacturing technique or manufacturing technology. For example, other examples can use layer-additive processes, layer-subtractive processes, hybrid processes, etc.

Suitable additive manufacturing techniques in accordance with the present disclosure include, for example, Fused Deposition Modeling (FDM), Selective Laser Sintering (SLS), 3D printing such as by inkjets, laser jets, and binder jets, Sterolithography (SLA), Direct Selective Laser Sintering (DSLS), Direct Metal Laser Sintering (DMLS), Electron Beam Sintering (EBS), Electron Beam Melting (EBM), Laser Engineered Net Shaping (LENS), Laser Net Shape Manufacturing (LNSM), Direct Metal Deposition (DMD), Digital Light Processing (DLP), Direct Selective Laser Melting (DSLM), Selective Laser Melting (SLM), Direct Metal Laser Melting (DMLM), and other known processes.

The additive manufacturing processes described herein can be used to form components using a variety of material. For example, the material can be plastic, metal, concrete, ceramic, polymer, epoxy, photopolymer resin, and/or any other suitable material that may be in solid, liquid, powder, sheet material, wire, or any other suitable form or combinations thereof. In certain examples, the additively manufactured components described herein may be formed in part, in whole, or in some combination of materials including but not limited to pure metals, nickel alloys, chrome alloys, titanium, titanium alloys, magnesium, magnesium alloys, aluminum, aluminum alloys, and nickel or cobalt based superalloys. In certain examples, the combustor dome 202 and/or other components of the combustion section 126 can be formed using a high-temperature material such as a cobalt allow, a nickel alloy, and/or a combination such as a HS188, 625, and/or 817 alloy. These materials are examples of materials suitable for use in the additive manufacturing processes described herein, and may be generally referred to as “additive materials.”

In addition, one skilled in the art will appreciate that a variety of materials and methods for bonding those materials may be used and are contemplated as within the scope of the present disclosure. As used herein, references to “fusing” may refer to any suitable process for creating a bonded layer of any of the above materials. For example, if an object is made from polymer, fusing may refer to creating a thermoset bond between polymer materials. If the object is epoxy, the bond may be formed by a crosslinking process. If the material is ceramic, the bond may be formed by a sintering process. If the material is powdered metal, the bond may be formed by a melting or sintering process. One skilled in the art will appreciate that other methods of fusing materials to make a component by additive manufacturing are possible, and the presently disclosed subject matter may be practiced with those methods.

In addition, the additive manufacturing process disclosed herein allows a single component to be formed from multiple materials. Thus, the components described herein may be formed from any suitable mixtures of the above materials. For example, a component may include multiple layers, segments, or parts that are formed using different materials, processes, and/or on different additive manufacturing machines. In this manner, components can be constructed which have different materials and material properties for meeting the demands of any particular application. In addition, although the components described herein are constructed entirely by additive manufacturing processes, it should be appreciated that in alternate examples, all or a portion of these components can be formed via casting, machining, and/or any other suitable manufacturing process. Indeed, any suitable combination of materials and manufacturing methods can be used to form these components.

An example additive manufacturing process will now be described. Additive manufacturing processes fabricate components using 3D object information, such as a three-dimensional computer model, of the component (e.g., the combustor dome 202).

Accordingly, a three-dimensional design model of the component can be defined prior to manufacturing. In this regard, a model or prototype of the component can be scanned to determine the three-dimensional information of the component. As another example, a model of the component can be constructed using a computer aided design (CAD) program to define the three-dimensional design model of the component.

The design model can include 3D numeric coordinates of the entire configuration of the component including both external and internal surfaces of the component. For example, the design model can define the body, the surface, and/or internal passageways such as openings, support structures, etc. In one example, the three-dimensional design model is converted into a plurality of slices or segments, such as along a central (e.g., vertical) axis of the component or other axis. Each slice may define a thin cross section of the component for a predetermined height of the slice. The plurality of successive cross-sectional slices together form the 3D component. The component is then “built-up” slice-by-slice, or layer-by-layer, by the additive manufacturing apparatus until the component finished (e.g., the component is formed).

In this manner, the components described herein, such as the combustor dome 202, can be fabricated using the additive process, or more specifically each layer is successively formed, such as by fusing or polymerizing a plastic using laser energy or heat or by sintering or melting metal powder. For example, a particular type of additive manufacturing process may use an energy beam, for example, an electron beam or electromagnetic radiation such as a laser beam, to sinter or melt a powder material. Any suitable laser and laser parameters may be used, including considerations with respect to power, laser beam spot size, and scanning velocity. The build material can be formed by any suitable powder or material selected for enhanced strength, durability, and useful life, particularly at high temperatures.

Each successive layer may be, for example, between about 10 μm and 200 μm, although the thickness may be selected based on any number of parameters and may be any suitable size according to alternative embodiments. Therefore, utilizing the additive formation methods described above, the components described herein may have cross sections as thin as one thickness of an associated powder layer, e.g., 10 μm, utilized during the additive formation process.

In addition, utilizing an additive process, the surface finish and features of the components can vary as need depending on the application. For example, the surface finish may be adjusted (e.g., made smoother or rougher) by selecting appropriate laser scan parameters (e.g., laser power, scan speed, laser focal spot size, etc.) during the additive process, especially in the periphery of a cross-sectional layer which corresponds to the part surface. For example, a rougher finish can be achieved by increasing laser scan speed or decreasing the size of the melt pool formed, and a smoother finish can be achieved by decreasing laser scan speed or increasing the size of the melt pool formed. The scanning pattern and/or laser power can also be changed to change the surface finish in a selected area.

Notably, several features of the components described herein were previously not possible due to manufacturing restraints. Certain examples utilize advances in additive manufacturing techniques to develop examples of such components generally in accordance with the present disclosure. While the present disclosure is not limited to the use of additive manufacturing to form these components generally, additive manufacturing does provide a variety of manufacturing advantages, including ease of manufacturing, reduced cost, greater accuracy, etc. More specifically, the passages, tubes, or bores 410 and associated openings 310, 320 in the combustor dome 202 are difficult to be formed (and cannot integrally be formed) without additive manufacturing.

In this regard, utilizing additive manufacturing methods, even multi-part components may be formed as a single piece of continuous metal, and may thus include fewer sub-components and/or joints compared to prior designs. The integral formation of these multi-part components through additive manufacturing can advantageously improve the overall assembly process as well as the structural integrity and usefulness of resulting parts such as the combustor dome 202, ferrule 220, etc. For example, the integral formation reduces the number of separate parts that must be assembled, thus reducing associated time and overall assembly costs. Additionally, existing issues with, for example, leakage, joint quality between separate parts, and overall performance may advantageously be reduced.

Also, the additive manufacturing methods described above enable much more complex and intricate shapes and contours of the components described herein. For example, components, such as the example combustor dome 202, can include passages extending through the combustor dome 202 from a set of first openings 310 to a set of second openings 320. In addition, the additive manufacturing process enables the manufacture of a single component having different materials such that different portions of the component may exhibit different performance characteristics. The successive, additive nature of the manufacturing process enables the construction of these novel features. As a result, the components described herein may exhibit improved functionality and reliability.

FIG. 11 is a flow diagram of an example additive manufacturing process 1100 to form the example combustor dome 202 of FIGS. 3-10 . At block 1110, parameters defining the combustor dome 202 are processed. For example, a model, file, set of definitions, etc., defining the dimensions and/or other characteristics of the combustor dome or liner 202 including a number, placement, and dimension of the plurality of first openings 310, passages 410, and the plurality of second openings 320 is processed by a controller associated with an additive manufacturing apparatus (e.g., a 3D printer). For example, a size of the plurality of first openings 310, a size of the plurality of second openings 320, and/or a size of the plurality of passages 410 can be set according to an amount of air flow and cooling to be provided by the combustor dome 202. Sizing may differ within each of the pluralities 310, 320, 410, for example. Sizing can be customizable based on aerodynamics and/or heat transfer, for example.

At block 1120, the combustor dome 202 is formed according to the parameters by the additive manufacturing apparatus. For example, a reservoir or other supply of high temperature material such as a cobalt alloy, nickel alloy, etc., is used to form the combustor dome 202 using a DMLM additive manufacturing apparatus, a DMLS additive manufacturing apparatus, a binder jet additive manufacturing apparatus, etc. At block 1130, the combustor dome 202 is released from the additive manufacturing apparatus and is available for packaging, sale, installation, etc.

From the foregoing, it will be appreciated that the disclosed apparatus enables improved air flow and cooling of the combustion section 126 through improved design of the combustor dome 202. A technical effect of the integration of passages 410 through the combustor dome 202 is to enable a new, cooling air flow distinct from impingement cooling, film cooling, and other prior efforts. The combustor dome 202 with integrated bore cooling provides a technical effect of improved, more efficient combustor cooling as well as increased reliability of the combustor dome 202, improved ease of manufacture of an integral part, and improve combustion operation. Using additive manufacturing, the combustor dome or liner 202 can be smaller and lighter weight than traditional, multi-pat dome designs with impingement cooling, while providing improved cooling air flow through integrated air flow passages. The air flow passages may not have a constant diameter. Instead, air flow passages can be uniquely sized to reduce pressure drop and maximize cooling, for example.

The presently described technology can be implemented according to a plurality of examples. In certain examples, the plurality of first openings 310 provides an inlet means, and the plurality of second openings 320 provides an outlet means. In certain examples, the plurality of passages 410 provides a passage means connecting the inlet means to the outlet means within the combustor dome 202. In certain examples, the inlet means, the outlet means, and the passage means are formed integral to the combustor dome 202 and allow air to travel from the inlet means to the outlet means via the passage means. In certain examples, the ferrule 220 provides a fuel-air entry means.

Although certain example methods, apparatus and articles of manufacture have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the claims of this patent.

The following claims are hereby incorporated into this Detailed Description by this reference, with each claim standing on its own as a separate embodiment of the present disclosure.

Further aspects of the present disclosure are provided by the subject matter of the following clauses:

Certain examples provide a combustor dome for a combustion section of a turbine engine. The example combustor dome forms an integral part including: a plurality of first openings; a plurality of second openings; and a plurality of passages formed in the combustor dome connecting respective ones of the plurality of first openings with respective ones of the plurality of second openings, wherein the combustor dome is configured to allow air to enter through the plurality of first openings and travel through the plurality of passages to exit through the plurality of second openings, the air to transfer heat from the combustion section.

The combustor dome of any preceding clause, wherein the combustor dome is to be formed from additive manufacturing.

The combustor dome of any preceding clause, wherein the combustor dome is formed of at least one of a cobalt alloy or a nickel alloy.

The combustor dome of any preceding clause, further including a ferrule.

The combustor dome of any preceding clause, further including an igniter port.

The combustor dome of any preceding clause, wherein a size of the plurality of first openings and a size of the plurality of second openings corresponds to an amount of air flow and cooling to be provided by the combustor dome.

The combustor dome of any preceding clause, wherein a size of the plurality of passages is customizable based on at least one of aerodynamics or heat transfer.

Certain examples provide a combustion section of a turbine engine, the combustion section including: a combustion chamber; and a combustor dome enclosing at least a portion of the combustion chamber, the combustor dome including: a plurality of first openings; a plurality of second openings; and a plurality of passages formed in the combustor dome connecting respective ones of the plurality of first openings with respective ones of the plurality of second openings, wherein the combustor dome is configured to allow air to enter through the plurality of first openings and travel through the plurality of passages to exit through the plurality of second openings, the air to transfer heat from the combustion chamber.

The combustion section of any preceding clause, wherein the combustor dome is to be formed from additive manufacturing.

The combustion section of any preceding clause, wherein the combustor dome is formed of at least one of a cobalt alloy or a nickel alloy.

The combustion section of any preceding clause, further including a ferrule.

The combustion section of any preceding clause, wherein the ferrule is integrated with the combustor dome.

The combustion section of any preceding clause, further including an igniter port.

The combustion section of any preceding clause, wherein a size of the plurality of first openings and a size of the plurality of second openings corresponds to an amount of air flow and cooling to be provided by the combustor dome.

The combustion section of any preceding clause, wherein a size of the plurality of passages is customizable based on at least one of aerodynamics or heat transfer.

Certain examples provide a combustor liner of a turbine engine, the combustor liner including: an inlet means; an outlet means; and a passage means connecting the inlet means to the outlet means within the combustor liner, wherein the inlet means, the outlet means, and the passage means are formed integral to the combustor liner and allow air to travel from the inlet means to the outlet means via the passage means.

The combustor liner of any preceding clause, wherein the combustor liner is to be formed from additive manufacturing.

The combustor liner of any preceding clause, wherein a size of the inlet means and a size of the outlet means corresponds to an amount of air flow and cooling to be provided by the combustor liner.

The combustor liner of any preceding clause, wherein a size of the passage means is customizable based on at least one of aerodynamics or heat transfer.

The combustor liner of any preceding clause, further including a fuel-air entry means.

Certain examples provide a combustion section of a turbine engine. The example combustion section includes a combustion chamber and a combustor dome enclosing at least a portion of the combustion chamber. The example combustor dome includes: an inlet means; an outlet means; and a passage means connecting the inlet means to the outlet means within the combustor dome. The inlet means, the outlet means, and the passage means are formed integral to the combustor dome and allow air to travel from the inlet means to the outlet means via the passage means.

The combustion section of any preceding clause, wherein the combustor dome is to be formed from additive manufacturing.

The combustion section of any preceding clause, wherein the combustor dome is formed of at least one of a cobalt alloy or a nickel alloy.

The combustion section of any preceding clause, further including a ferrule.

The combustion section of any preceding clause, wherein the ferrule is integrated with the combustor dome.

The combustion section of any preceding clause, further including a fuel-air entry means.

The combustion section of any preceding clause, wherein a size of the inlet means and a size of the outlet means corresponds to an amount of air flow and cooling to be provided by the combustor dome.

The combustion section of any preceding clause, wherein a size of the passage means is customizable based on at least one of aerodynamics or heat transfer. 

1. A combustor dome for a combustion section of a turbine engine, the combustor dome forming an integral part of a material, the combustor dome comprising: a plurality of first openings; a plurality of second openings; and a plurality of passages formed in the combustor dome connecting respective ones of the plurality of first openings with respective ones of the plurality of second openings, each passage extending through the material of the combustor dome from the respective first opening to the respective second opening, the respective passage including a first portion extending along a first axis within the material of the combustor dome and a second portion extending along a second axis within the material of the combustor dome, wherein the combustor dome is configured to allow air to enter through the plurality of first openings and travel through the plurality of passages to exit through the plurality of second openings, the air to transfer heat from the combustion section.
 2. The combustor dome of claim 1, wherein the combustor dome is formed from additive manufacturing.
 3. The combustor dome of claim 1, wherein the material includes at least one of a cobalt alloy or a nickel alloy.
 4. The combustor dome of claim 1, further including a ferrule.
 5. The combustor dome of claim 1, further connected to an igniter port.
 6. The combustor dome of claim 1, wherein a size of the plurality of first openings and a size of the plurality of second openings corresponds to an amount of air flow and cooling to be provided by the combustor dome.
 7. The combustor dome of claim 1, wherein a size of the plurality of passages is customizable based on at least one of aerodynamics or heat transfer.
 8. A combustion section of a turbine engine, the combustion section comprising: a combustion chamber; and a combustor dome enclosing at least a portion of the combustion chamber, the combustor dome formed of a material and including: a plurality of first openings; a plurality of second openings; and a plurality of passages formed in the combustor dome connecting respective ones of the plurality of first openings with respective ones of the plurality of second openings, each passage extending through the material of the combustor dome from the respective first opening to the respective second opening, the respective passage including a first portion extending along a first axis within the material of the combustor dome and a second portion extending along a second axis within the material of the combustor dome, wherein the combustor dome is configured to allow air to enter through the plurality of first openings and travel through the plurality of passages to exit through the plurality of second openings, the air to transfer heat from the combustion chamber.
 9. The combustion section of claim 8, wherein the combustor dome is formed from additive manufacturing.
 10. The combustion section of claim 8, wherein the material includes at least one of a cobalt alloy or a nickel alloy.
 11. The combustion section of claim 8, further including a ferrule.
 12. The combustion section of claim 11, wherein the ferrule is integrated with the combustor dome.
 13. The combustion section of claim 8, further including an igniter port.
 14. The combustion section of claim 8, wherein a size of the plurality of first openings and a size of the plurality of second openings corresponds to an amount of air flow and cooling to be provided by the combustor dome.
 15. The combustion section of claim 8, wherein a size of the plurality of passages is customizable based on at least one of aerodynamics or heat transfer.
 16. A combustor liner of a turbine engine, the combustor liner comprising: an inlet means; an outlet means; and a passage means connecting the inlet means to the outlet means within the combustor liner, wherein the inlet means, the outlet means, and the passage means are formed integral to the combustor liner and allow air to travel from the inlet means to the outlet means via the passage means, the passage means extending through material of the combustor liner from the inlet means to the outlet means, the passage means including a first portion extending along a first axis and a second portion extending along a second axis.
 17. The combustor liner of claim 16, wherein the combustor liner is formed from additive manufacturing.
 18. The combustor liner of claim 16, wherein a size of the inlet means and a size of the outlet means corresponds to an amount of air flow and cooling to be provided by the combustor liner.
 19. The combustor liner of claim 16, wherein a size of the passage means is customizable based on at least one of aerodynamics or heat transfer.
 20. The combustor liner of claim 16, further connected to a fuel-air entry means. 